The flags are back up at Bondi Beach late yesterday, but thick red algal blooms were continuing to appear at beaches across Sydney's east.

A bloom was first spotted at Bondi at 6.30am (8.30am NZT) on Tuesday, with subsequent outbreaks popping up at Clovelly Beach and Gordons Bay later in the day.

On the New South Wales central coast, blooms were spotted off Wamberal, Copacabana, Terrigal, Avoca and North Avoca beaches at around 9.30am but dispersed shortly after, a Gosford City Council spokesperson said.